黒羽織・くろはおり・kurobaori
Literally black haori. Black haori come without and with one or more kamon (family crest, 紋付黒羽織・montsuki kurobaori).
Black haori are versatile since they easy combine with most kimono, and if the haori has a kamon they can make a regular kimono a little more formal.
Not everybody could afford to own a black haori so it was not uncommon to borrow a black haori from your landlord for a formal occasion.
There was a period when it was ninki (popular) to own a black haori and Oshima tsumugi kimono combination.